I have a lot of vehicles with old batteries, and I am tired of constantly going out to start something with a dead battery.
To fix this issue I ordered a solar 12v maintainer for my truck battery.
This version was lass that $25.00 and it came with multiple ways to install it on the truck.
I liked the long leads on the Solar 12v Maintainer, it allowed me to set the solar panel where I needed it, and still hook to the battery.
This is a solar battery maintainer, not a charger, so it is not designed to charge a dead battery, but rather to ensure a constant trickle charge to keep a battery in good working condition.